1,330
edits
SMV file format: Difference between revisions
add link to A. Arvai's SMV library
No edit summary |
(add link to A. Arvai's SMV library) |
||
| (2 intermediate revisions by one other user not shown) | |||
| Line 1: | Line 1: | ||
The SMV file format is a broad standard x-ray diffraction image file format that appeared with the first CCD-based x-ray detectors. SMV stands for Super Marty View, a program written by Dr. Martin "Marty" Stanton to display the images form the original SBC CCD detector. The format is largely informal, the only rigid rule is that the file header is text and begins with the string: "\ | The SMV file format is a broad standard x-ray diffraction image file format that appeared with the first CCD-based x-ray detectors. SMV stands for Super Marty View, a program written by Dr. Martin "Marty" Stanton to display the images form the original SBC CCD detector. The format is largely informal, the only rigid rule is that the file header is text and begins with the string: "{\nHEADER_BYTES=", where \n is the newline character (ASCII decimal code 13). This string must be followed with an ASCII number indicating the number of bytes in the header before the start of the image data. The header itself is generally expected to be all text and describe the nature of this image data in a keyword=value type format. The most common SMV header is 512 bytes. So common in fact that many data processing programs assume that it is without reading the HEADER_BYTES entry. An example of such a 512-byte header is given here: | ||
| Line 54: | Line 54: | ||
* OSC_RANGE - change in value of spindle rotation motor for this image. | * OSC_RANGE - change in value of spindle rotation motor for this image. | ||
* WAVELENGTH - X-ray wavelength used to obtain this image. All known SMV file formats give this in Angstrom. | * WAVELENGTH - X-ray wavelength used to obtain this image. All known SMV file formats give this in Angstrom. | ||
* BEAM_CENTER_X - position on the detector face that would be hit by the direct x-ray beam if the beamstop were removed. Most beamlines give this in millimeters, but some at ESRF give it in pixel units. Unfortunately, there are also | * BEAM_CENTER_X - position on the detector face that would be hit by the direct x-ray beam if the beamstop were removed. Most beamlines give this in millimeters, but some at ESRF give it in pixel units. Unfortunately, there are also eight possible conventions for representing the beam center (four corners to use as 0,0, and two axes to assign to either "X" or "Y"), and nearly all of these are used by one program or another. At the Advanced Light Source and Stanford Synchrotron Radiation Lab these values are such as to give the correct beam center display in the program ADXV (provided by ADSC). | ||
* DENZO_X_BEAM - introduced at the Advanced Light Source to indicate the direct beam position to enter into the data processing program denzo or mosflm, as these programs coincidentally use the same beam center convention. This was an attempt to avoid confusion by specifying the convention explicitly. | * DENZO_X_BEAM - introduced at the Advanced Light Source to indicate the direct beam position to enter into the data processing program denzo or mosflm, as these programs coincidentally use the same beam center convention. This was an attempt to avoid confusion by specifying the convention explicitly. | ||
Here is a library and documentation to read/write ADSC SMV/IMG files: http://www.scripps.edu/~arvai/adxv/data/smv.tar.gz | |||
== See also == | == See also == | ||
[[Crystallographic data file formats]] | [[Crystallographic data file formats]] | ||